The invention relates to a special electrode surface for electrodes of magnetically inductive flow meters.
The theoretical calculation of the size of electrode surfaces in IFMs is based on point-like electrodes which, however, are never achievable in practice. The electrodes used are normally ones whose diameter is several mm or cm in diameter depending on the rated width, in order to be able to seal them into a clad measurement tube. According to experience, the contact resistance between the electrode and the medium is not equal everywhere, rather the position of least junction resistance migrates statistically around on the electrode surface.
A displacement along the diagonal reduces the measurement sensitivity, which is thus subject to statistical fluctuations. A shift in the axial direction means the displacement of a piece of a conductor loop in the magnetic field. A voltage is therefore induced, which is superimposed on the measurement voltage.
It is an object of the invention to avoid these disadvantages.